The invention relates to an electric machine, in particular for a drive apparatus for a motor vehicle, comprising a rotor shaft, which is mounted rotatably in a housing, comprising a sliding device, which has at least two slip rings arranged in rotationally fixed fashion on the rotor shaft and at least two sliding contacts, which are arranged in the housing and interact with in each case one of the slip rings, and comprising a rotation angle detection device, which has at least one rotation angle encoder arranged on the rotor shaft and at least one rotation angle sensor arranged in the housing for detecting the rotation angle encoder,
Electric machines of the type mentioned at the outset are known from the prior art. In general, an electric machine has a rotor, which is mounted on a rotor shaft and which interacts with a stator arranged in a housing bearing the rotor shaft. In particular when the electric machine is intended to be operated as a motor, an electrical connection to a rotor winding of the rotor needs to be provided, but this electrical connection cannot be represented easily owing to the rotational movement of the rotor. It is known to provide a slip ring device which has at least two slip rings arranged in rotationally fixed fashion on the rotor shaft and at least two sliding contacts, for example sliding brushes, which are arranged fixedly in the housing and interact with in each case one of the slip rings. The sliding contacts are in touching contact with the respective slip ring and thus produce an electrical contact in any rotation angle position of the rotor. In order to be able to drive the electric machine correctly, a rotation angle detection device is also provided, which comprises a rotation angle encoder and a rotation angle sensor. The rotation angle encoder is arranged on the rotor shaft, with the result that the position of the rotation angle encoder correlates with the rotation angle position of the rotor shaft. The rotation angle sensor, on the other hand, is arranged on the housing and is aligned in such a way that it detects the rotation angle encoder in order to be able to detect or determine the position of the rotation angle encoder and therefore the rotation angle position of the rotor shaft.